001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.camel.processor; 018 019 import org.apache.camel.AsyncCallback; 020 import org.apache.camel.Exchange; 021 import org.apache.camel.Processor; 022 import org.slf4j.Logger; 023 import org.slf4j.LoggerFactory; 024 025 /** 026 * An {@link org.apache.camel.processor.ErrorHandler} used as a safe fallback when 027 * processing by other error handlers such as the {@link org.apache.camel.model.OnExceptionDefinition}. 028 * 029 * @version 030 */ 031 public class FatalFallbackErrorHandler extends DelegateAsyncProcessor implements ErrorHandler { 032 033 private static final Logger LOG = LoggerFactory.getLogger(FatalFallbackErrorHandler.class); 034 035 public FatalFallbackErrorHandler(Processor processor) { 036 super(processor); 037 } 038 039 @Override 040 public boolean process(final Exchange exchange, final AsyncCallback callback) { 041 // support the asynchronous routing engine 042 boolean sync = processor.process(exchange, new AsyncCallback() { 043 public void done(boolean doneSync) { 044 if (exchange.getException() != null) { 045 // an exception occurred during processing onException 046 047 // log detailed error message with as much detail as possible 048 Throwable previous = exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Throwable.class); 049 String msg = "Exception occurred while trying to handle previously thrown exception on exchangeId: " 050 + exchange.getExchangeId() + " using: [" + processor + "]."; 051 if (previous != null) { 052 msg += " The previous and the new exception will be logged in the following."; 053 LOG.error(msg); 054 LOG.error("\\--> Previous exception on exchangeId: " + exchange.getExchangeId() , previous); 055 LOG.error("\\--> New exception on exchangeId: " + exchange.getExchangeId(), exchange.getException()); 056 } else { 057 LOG.error(msg); 058 LOG.error("\\--> New exception on exchangeId: " + exchange.getExchangeId(), exchange.getException()); 059 } 060 061 // we can propagated that exception to the caught property on the exchange 062 // which will shadow any previously caught exception and cause this new exception 063 // to be visible in the error handler 064 exchange.setProperty(Exchange.EXCEPTION_CAUGHT, exchange.getException()); 065 066 // mark this exchange as already been error handler handled (just by having this property) 067 // the false value mean the caught exception will be kept on the exchange, causing the 068 // exception to be propagated back to the caller, and to break out routing 069 exchange.setProperty(Exchange.ERRORHANDLER_HANDLED, false); 070 } 071 callback.done(doneSync); 072 } 073 }); 074 075 return sync; 076 } 077 078 @Override 079 public String toString() { 080 return "FatalFallbackErrorHandler[" + processor + "]"; 081 } 082 }